Production of drying oils



Patented Sept. 27, 1938 UNITED STATES PATENT orFicE' 2,131,195 PRODUCTION or name oILs" Helmuth G. Schneider and Julius V. Sommer,

Elizabeth, N. .l., assignorsto Standard Oil Development Company, a corporation of Delaware No Drawing. Application June 9, 1934,

' I Serial No. 729,800

14 Claims.

This invention relates to the production of drying oils from hydrocarbons and especially from petroleum oils.

It is well known that vapor phase cracked gasolines, especially gasolines. produced by vapor phase cracking of high boiling mineral oils at a temperature of about 1100 F. and at a pressure p of not over 150 pounds per square inch, are less stable on storage than ordinary cracking coil distillates. It is believed that this is due to the presence of aromatic and unsaturated. compounds,

especially unsaturated compounds of the diolecracked gasolines boiling up to 300 C. are prefseparated preferably by- 'means of vacuum distillation, and polymerized.

erentially oxidized,

The oxidation of the diolefinestakes place more readily than ordinary olefines and the mechanism of the oxidation does not appear to be the same for the two types of unsaturated compounds.

In many respects the oxidation of the diolefines resembles the drying of linseed oil.

Therefore, the diolefines are readily oxidized in the presence of saturated and unsaturated compounds and the oxidized diolefines are separated by means of distillation. The oxidation is generally carried out inthe liquid phase and at a temperature'of about to 150 C. and under superatmospheric pressures. For example, partial oxidation at C. and pounds pressure per square inchofv vapor phase distillate with subsequent removal of the lighter unoxidized material by distillation yields a heavy oil which dries to a non-tac y film when exposed to the air. This drying oil resembles linseed oil in that: (a) it'absorbs oxygen from the air during the drying; (b) it graduallyincreases in viscosity on being kept at about 150 C.; (c) it dries more'rapidly after being boiled; (d) driers such as cobalt, lead,

copper, and manganese oleates greatly increase the rate of oxidation and decrease the drying (Cl. res-142i time when the oil is exposed in thinfilms. The r film formed on drying does not finger mark.

It has also been found that certain fractions of vapor phase cracked gasoline yield better drying oils than others. Fractions boiling between 40 C. and 108 C. and between C. and 145 C. give the largest yields. Another factor that atfects the yields is the amount of oxygen absorbed which varies as to the particular distillate used. However, large amounts of air or oxygen should-be avoided sincethe quality of the drying oil drops off in proportion and a point is reached where the oxidized product no longer dries to a solid fllm as can be seen below.

Vapor phase gasolines, obtained bycracking at substantially atmospheric pressure, contain about 11% of diolefines and yield about 5% of drying oils under normal operating conditions. However, by polymerizing at 230 C. and under approximately 1,000 to 1,500 .pounds per square inch pressure of nitrogen containing'a very small per-.-

centage of air such as enough tomake the oxygen content' about 5%, the yield of drying oil was raised to 6-11% and the resulting oil, on drying, formed a hard film.

In order to obtain a colorless drying oil, it has been found necessary to" first treat the gasoline to remove any sulfur compounds that may be present. This is generally done by refluxing the gasoline with metallic sodium, copper oxide or" lead oxide. 1

The following example illustrates the effect of time of oxidation on the yield and quality of the drying .oil:

. Drying time for pressure drop of250 mm. 'limeoi oxidation Yield oiudrying o Without drier With drier Percent Hours I aura 3 2 hrs 4. 2 7hrs 6.8 (t) l37 11 hrs: l 7. 0 (1') 180 15 hrs 8.5 b (t) (i) To compare the drying properties of oils, the rate of oxygen absorption is given-as the time in hours required for a pressure drop of 250 mm. of mer in ,a closed system containing known volumes oi the respective oi 5 attached to a manometer containing oxygen.

TDid not give the required pressure drop in 200 hrs.

The following table gives results of tests of three drying oils, described below, which illustrate the rate of oxygen absorption of the drying oils or the present invention, as compared with linseed oil:-

- oil obtained from a ggffggf fgggf I inseed oil Oil w 011%" Oil Mm. Mm. Mm. Mm.

. 1o a0 so no 55 10 11s 200 4 ess vapor phase cracking of a Mid-Continent oil.

It has been found that while the drying oils produced by oxidation of vapor phase gasoline at about 100 C. and 110 pounds air pressure possess many of the characteristics of linseed oil, the film produced on drying was too soft as it could be scratched with a finger nail. It has been found that a drying oil that dries to a harder film can be produced (1) by taking the oxidized drying oil produced by contacting with oxygen at 100 C. and 110 pounds air pressure for about 3 hours, and treating the oil further by polymerization with nitrogen at more elevated temperatures and pressures, such as about 230 C. and 1500 lbs. per sq. in. for 17 hours.

(2) By oxidation ofthe gasoline with air (or an inert gas containing about 10 to 50% of oxygen) at more elevated temperatures and pressures such as about 230 C. and 1500 lbs. per

sq. in. for 17 hours so as to speed up the rate of initial polymerization during the oil, or

(3) By polymerizing the diolefincs and gasoline at high pressures and in the presence of traces of oxygen such as 0.01 to 2.0% at about 230 C. for about 17 hours.

Larger amounts of the drying oil are produced the formation of by oxidation and polymerization at more elevated temperatures and pressures. A drying oil can be prepared from vapor phase cracked gasoline which, on exposure to air, dries to a hard film. The preferred temperatures and pressures forthe production of drying oils from vapor phase gasoline are approximately 200 C. and 1000 to 1500 pounds per square inch respectively. The following example illustrates the eflects on a drying oil of the addition of 0.2% of a drier, such as cobalt oleate, on the drying rate. The rate of oxidation is given as the time required for a pressure drop of 250 mm.

The oils used were obtained by oxidation of the diolefine, separated and polymerized. o

' In the appending claims the term oxygen" is intended to mean free molecular oxygen substantially free from any ozone.

comprises subjecting a fraction of gasoline nor-' mally boiling between the approximate limi s of 40 and 108 C. and obtained byvapor phase cracking of higher boiling mineral oils at a pressure of not over about 150 lbs. per square inch, in liquid phase to the action of a. gas containing oxygen at a temperature between thz. approximate limits of 50 and 150 C. and at pressure of about 100 lbs. per square inch, and

recovering a drying oil from the product by distillation.

2. A process for producing a drying oil which comprises subjecting a fraction 01 gas-01inobtained by vapor phase cracking of higher boiling mineral oils, in liquid phase to the action of a gas containing oxygen at a pressure substantially above atmospheric and at a temperature of about 50 to 230 C., recovering a drying. oil from the product by distillation and polymerizing said drying oil at elevated temperature and pres sure.

3. Process according to claim 2 in which the final polymerization step is carried out at a temperature of about 200 C. and at a pressure of about 1000 lbs. per square inch.

4. A process for producing oxidized-hydrocarbons, which comprises subjecting in the liquid phase to the action of a gas containing oxygen at a pressure substantially above atmospheric and at a temperature of about 50 to 230 C., a narrow cut gasoline fraction having a boiling range spread of not over about 70 C. and capable of yielding superior oxidized hydrocarbons than a gasoline derived from the same crude petroleum but having the usual wide boiling range, said fraction to be treated with oxygen having been obtained by vapor phase cracking of higher boiling mineral oils.

5. Process according to claim 4 carried out at a temperature below about 150 C.

6. Process according to claim4 carried out at a temperature betweenth'e approximate limits of and 150 C. and at a pressure above about 100 pounds per square inch.

7. Process according to claim 4 carried out at a temperature above about 200 C. 'and at a pressure above about 1000 pounds per square inch.

8. Process according to claim 4 carried out at a temperature above about 200 C. and at a pressure above about 1000 pounds per square inch, using a gas containing not more than about 5% oxygen. I

9. Process according to claim 4 in which the gasoline fraction treated is subjected to a preliminary sulfur removal treatment in order to produce a substantially colorless finished drying oil 10. Process according to claim 4 in which a gasoline fraction normally boiling between the approximate limits of 40 and 108 C. is treated.

11. Process according to claim 4 in which a gasoline fraction 'normally boiling between the approximate limits of 130 and 145 C. is treated.

12. A process for producing a drying-oil, which comprises subjecting in liquid phase to the action of a gas containing oxygen, at a pressure substantially above atmospheric and at a temperature of about 50 to 230 C. and for a time adapted to produce optimum drying oil properties, a narrow cut gasoline fraction having a boiling range spread of not over about 70 C. and

capable of yielding superior drying oils than the whole gasoline of the usual wide boiling range,

10' gasoline obtained by vapor phase cracking of higher boiling mineral oi s, in liquid phase to the action of a gas containing oxygen, at a temperature between the approximate limits of 200 and 230 C. and a pressure above about 1000 pounds per square inch.

14. Process according to claim 13 in which an oxidizing gas is used containing not more than about 5% of oxygen.

G. SCHNEIDER, JULIUS ,V. SOMMER. 

